This invention relates to a process for the manufacture of Sucrose-free, dietetic and/or teeth-sparing chocolate.
As sucrose substitutes, sugar alcohols for example can be used, such as sorbitol, mannitol, maltitol, lactitol, xylitol, "PALATINIT", i.e., isomalt etc., or also the teeth-sparing disaccharide "PALATINOSE", i.e., isomaltose leucrose and polydextrose, as well as mixtures thereof. These sucrose substitutes are combined with milk products such as unsweetened evaporated milk, whole-milk powder, skimmed-milk powder or milk product derivatives (free of lactose or containing lactose) with or without the addition of chocolate liquor containing up to 50% native cocoa butter, cocoa powder, cocoa butter or milk fat, if desired with the further addition of other substances such as emulsifiers (e.g. lecithin, PGPR, and ammonium salt of phosphatide acid (YN)), flavorings (vanilla etc.), sweeteners (cyclamate, saccharin, etc.).
Indeed, diabetic chocolate or teeth-sparing chocolate has already been manufactured by direct preparation from milk products, chocolate liquor containing up to 50% native cocoa butter and cocoa butter, with the use of sucrose substitutes. However, in its manufacture (rolling and tumbling) formation of agglomerates became apparent. These agglomerates form at the beginning of or during the tumbling process with the result that the end product has a gritty coarse texture. As was found, the cause lies, among other things, in the hygroscopic capacity of these products, namely their property of absorbing water. On the one hand, in the manufacture of the chocolate, water is absorbed from the air during the process and on the other hand, water comes into the product with the added raw substances such as milk powder, special milk product,chocolate liquor containing up to 50% native cocoa butter etc.; however, the water supplier can be the added sucrose substitute itself, for example when it has a large water content itself or if water is combined with it in the form of water of crystallization.
At the same time, the water content of the substance or the hygroscopic capacity upsets the fragmentation process (the rolling) considerably, with the result that even during the rolling, the desired refinements often can not be attained.
With certain sucrose substitutes (in the form supplied today) the technological reaction to the 5-rolling mills is also inadequate. The fluctuations in production and the inhomogeneity of the substance have a disadvantageous effect on the quality of the end product.
The crumb process serves as another basis for the production of chocolate. This process yields a distinctive chocolate flavour (attractive, caramel milk flavour, mild cocoa grades) and in addition to this, it brings about economic advantages (good storage stability, possible saving in tumbling time). Known crumb systems include, among others: Scott-Balfour system, crumb process according to Dr. Powell/Cadbury, Groen process. However, it is disadvantageous that one cannot employ all of the known crumb systems starting with products for the manufacture of sucrose-free, dietetic and/or teethsparing chocolates.
A further disadvantage of the sucrose substitutes employed in present-day form is the organoleptic properties of the diabetic and teeth-sparing milk chocolates. The reason lies in the observance of the low tumbling temperature (40.degree. to 50.degree. C.) made necessary by the physical properties (low melting point and/or water of crystalization) of the sucrose substitutes. The most important functions of the conche are degasification and mechanical-thermal treatment. It is known that during the tumbling, taste components can form by means of reactions between amino acids, reducing sugars, as well as other primary flavouring stages (taste-giving substances) of the chocolate liquor containing up to 50% native cocoa butter and milk constituents. In this connection the speed of the reaction, among other things, is dependent on the temperature. A refinement in taste obviously accompanies the improvement in consistency as a result of the tumbling. Another purpose of the tumbling is the removal of the water and other steam-volatile substances from the chocolate mass. In this process the steam also takes on the function of a means of transportation, namely a portion of the undesired taste components is removed from the chocolate mass by means of steam. This process is also dependent on temperature, time and consistency.
If the chocolate mass has too high a viscosity, the lateral forces are so great that during the tumbling, the temperatures cause the crystal surfaces of the sucrose substitutes to melt and agglomerates can form as a result.
Another explanation of this formation of agglomerates, which is more probable, is the following. The tumbling temperature (40.degree. to 50.degree. C.) of the chocolate mass has the effect that, during the tumbling process (6 to 24 hours), quantitatively more sucrose substitutes accumulate (dissolve) in the water, even if present in a small amount. The crystal surfaces are etched and thereby cause agglomeration of the sucrose substitute particles, at the same time as water loss. A portion of the sucrose substitutes crystallizes again or recrystallizes from this oversaturated solution. This leads to a growth of the sucrose substitute crystals already present and, on the other hand, to a change in the crystal structure.
Important factors in the formation of agglomerates are the chemical purity of the sucrose substitute used, the crystal shape (stable, unstable) and crystal structure thereof, the presence of water of crystallization, its solubility in water and the hygroscopic capacity.
The taste and the sweetness of chocolates can be substantially determined by the choice of the sucrose substitutes used. In the consumption of products which contain monosaccharide alcohol, the consumer experiences a cooling effect in the mouth caused by the differing solution enthalpy of the individual saccharides. The sugar alcohols xylitol, mannitol and sorbitol have high negative heats of solution and thereby give a non-typical taste. However, the consumer demands a taste impression which is similar to saccharose, that is to say, the sucrose alcohols (monosaccharides) mentioned above are less suitable for use in chocolates.